Low loss vibrator



Dec. 8, 1959 R. E. BARNES LOI LOSS VIBRA'I'OR Filed March e, 1957 INVENTOR 170% [fiarnas A'ITORNEY United States Patent LOW LOSS VIBRATOR Robert E. Barnes, Algona, Iowa, assignor to P. R. Mallory & Co., Inc., Indianapolis, Ind., a corporation of Delaware Application March 6, 1957, Serial No. 644,359

. 5 Claims. (Cl. 200-90) This invention relates generally to current interruptors known as vibrators for electrical circuits and more particularly' to such devices adapted for use in extremely low power applications.

In the development of the concepts of miniaturization to which the electrical arts have been progressing, it is desired that vibrator structures suitable for such developments be provided. Thus, such structures adapted for high frequency functions and for low power applications in which transistors are used, have by the present invention been provided for the first time. These applications, moreover, whether destined for military or civilian use, require that such devices withstand accelerations up to G and rotational accelerations from a position of rest to 10,000 rpm. in 20 l0- seconds and also require that the mechanism operate under conditions of rotation of up to 10,000 r.p.m. In addition to the rugged conditions under which these vibrators are to be used, it'is apparent that at high frequencies their low loss characteristics find general application in designs for low power miniaturized application.

Thus, the present invention of a low loss miniaturized vibrator mechanism is adapted to operate in low power circuits under conditions of extreme acceleration and ruggedness. :It comprises a cyclindrical casing acting as a frame therefor with each end being internally threaded. There are individual shoulders formed at opposite ends of the cylindrical casing. The vibrator includes a driver coil adapted to be current excited and has a pole piece penetrating the said coil. The pole piece, however, is staked to a threaded plug, and the driver coil is circumscribed by a coil container whereby the plug and pole piece are adapted to 'be threadably inserted into the internally threaded portion of the casing. The coil container is further adapted to be firmly held by and rest on the internal shoulder of the vibrator casing. The armature and reed assembly of the vibrator comprises a'vibratory reed having an armature at the end thereof and a plurality ofcontact bearing reed arms connected thereto. A pair of fixed side arms having contacts thereon are placed on each side'of said reed arms and are adapted to make contact therewith. In addition, a pair of'frame configured backing members for biasing the reed arms, and a novel stack means for supporting all of the above components sturdily on the opposite shoulder formed in the casing of the vibrator is provided. The entire casing is then sealed by means of a threaded plug which bears up against the. stack support to rigidly support the same. It is apparent, then, how ruggedly constructed all the parts of the vibrator are, even though they are extremely small in size. So sturdily constructed is the entire assembly that tremendous forces both of gravitation and acceleration are withstood in a manner heretofore unknown to the art.

Thus, it is. an object of the present invention to provide a vibrator for use in miniaturized circuits.

-Still another object of the present invention is to provide anew and novel vibrator mechanism particularly 2,916,581 Patented Dec. 8, 1959 adapted for use in transistor circuits and for use in high frequency devices.

Another object of the present invention is to provide a rugged low-power loss vibrator adapted for use in environments of extremely high rotational accelerations.

Another object is to provide a small, simple, and easily assembled interrupter device adapted to withstand severe gravitational forces.

Still another object of the present invention is to provide a simple, economical, and easily assembled interruptor device for use with miniaturized circuits and circuits calling for low power considerations.

This invention, accordingly, comprises the features of construction, combination of elements, arrangements of parts and methods of manufacture referred to herein or which will be brought out and exemplified in the disclosure as hereinafter set forth including the illustration of the drawings, the scope being understood from the appended claims.

For a further understanding of the nature of the invention as well as for specific disclosure thereof, reference should be madev to the following detailed description taken in connection with the drawing in which:

Fig. 1 is a vertical cross-sectional view of an embodiment of the vibrator of the present invention showing the constructional arrangement thereof;

Fig. 2 is a view of the above construction as taken along line 22 of Fig. 1 adapted to illustrate the compact stack mounting construction necessary to meet the acceleration and rugged physical standards set out for such an improved miniaturized device and;

Fig. 3 is an exploded view of the assembly of the vibrator as adapted to show cooperating constructional features thereof.

Generally speaking, the present low loss vibrator is directed toward providing a construction which is able to meet extreme requirements of ruggedness and rotational acceleration. These requirements, it is apparent, are requisite for advances in military and civilian technology in which vibratory devices are used. In addition, the electronic arts have presently advanced to where miniaturized vibrators are required without loss in the etficiencies thereof. Further, such vibrators in many instances, must be adapted for high frequency, low powered applications. These vibrators incorporating many improvements make them expressly important in circuit applications utilizing solid state amplifiers known as transistors. Further, in order to fulfill such requirements, the components of the present vibrator have been constructed so as to be included in an extremely small volume, here comprising a cylindrical casing. The vibrator, further, is constructed to offer a light weight assembly whose individual components afford high frequency operation under severe conditions of great radial acceleration, gravity and shock.

The figures of the drawing show the vibrator assembly or unit known as a low-loss vibrator. By definition a low loss vibrator is one which requires very little input power since its loss in operation is kept to a minimum. Although, a particular embodiment known as a half-wave-separate drive vibrator is shown, it is apparent to those skilled in the art, that the teachings illustrated thereby may be incorporated in other constructions, for example, of full wave-shunt drive; and full wave-series drive. Such vibrators are constructed for particular applications and purposes. For example, a half-wave, separate drive vibrator is especially used to handle low power outputs'of 10 watts or less under severe conditions of acceleration, shock and rotation. A full wave-shunt drive handles larger amounts of power, i.e. approximately 5-30 watts output; a full wave-separate drive vibrator is capable of handling power levels offrom 5-20-watts 3 output in rugged environments, and is intermediate between the former constructional types.

As seen from the figures of the drawing, the usual type of ferromagnetic frame of the vibrator has been replaced with a cylindrical case 11. A driver coil 12 is wound about an armature whose end comprises a pole piece 13. The vibratory system of the vibrator includes a vibratory reed 14, carrying a ferromagnetic armature 15. Reed arms 16 and 17 are adapted to swing with the reed and carry contacts such as 18, 19 at their free ends. These latter contacts are adapted to cooperate with fixed side contacts 20, 21. As those skilled in the art know, 'when the driver coil 12 is properly connected to a source of direct current as shown by the conductor 22 in addition to a conductor going from the coil and grounded to the case of the vibrator in Fig. l, the reed will be maintained in continuous vibration, with the frequency thereof being determined by the mass, compliance, and spacing relationship of the several parts and components.

Thus, in the present vibrator, the improved extremely miniaturized construction of the armature and reed assemblies, as related to their cooperative arrangement and mounting of the separate parts in the casing, makes possible a low-loss vibrator operable in extremely rugged environmental limits and under conditions of rapid gravitational and acceleration effects.

It is apparent that important improvements have been made in order to meet these extraordinary requirements called for by extremely rugged operational considerations. Thus in the present vibrator, the driver coil is wound on a brass form 23 having aluminum flanges 24. The pole piece 13 of the vibrator comprises a vertical dependency staked to a threaded plug 27. This plug is adapted to close off one end 32 of the cylindrical casing. The pole piece which is staked to the plug, penetrates the center of the driver coil to fit snugly therethrough. Moreover, the entire coil assembly is enclosed in a coil container 28. Thus, the entire assembly comprising the coil container, the coil, the end screw plug with pole piece, are all firmly retained in one end of a cylindrical case with the coil container at the base end resting on a ledge 30 formed on the inside of the case. This gives an extremely advantageous and rigid positioning for the entire coil assembly making it adapted to withstand tremendous forces.

Next, the stack assembly 31 of the vibrator is inserted from the opposite end 33 of the cylindrical casing 11 and is also held rigidly in position by means of a second threaded ring 34. The overall stack assembly in the casing is made up basically of two sections. There is the armature section which consists of an iron armature 15, a hinge 40, a hinge spacer to compensate for the thickness of binge 40 when necessary, two reed arms 16, 17, with contacts, and two .reed arm stops 41, 42. The armature section is held together firmly by two rivets which are hot upset. The armature section is in turn connected to the stack assembly bymeans of a hinge 40 The stack assembly, as shown in Figs. 2 and 3 consists of stack holding screws 50, 51, aninsulating bushing, a main stack support section 52, an insulator spacer, a side arm 53 with a contact, two insulating spacers, the armature assembly which is fastened in through the hinge 40, a solder lug, (not shown) an insulating spacer, a'second side arm assembly 54 with a contact, and the second half 55 of the stack support. The stack assembly is so designed that the parts are held in compression by the stack screws. The fibre bushing fits in such a manner that extremely little play is allowed in the other direction. The combination of the compression and the fit of the parts makes the assembly exceptionally rugged. The casehas ashoulder 70 upon which the stack-support rests. The base screwring 34 has been screwed in tightly against the outside of the stack support. The reed hinge of the vibrator is fixed by the dimensions of the insulating spacers in the stack. The air gap is adjustable by the use of spacer washers such as 71, between the shoulder of the case, and the stack support.

There are two basic models provided, the interruptor type and the self-rectifying type. The basic differences between the two models is in the reed arm and the side arms. The interruptor model has one contact on the reed arm and one contact on'the side arm. The self-rectifier type features a double reed arm and a double side-arm. The side arm coming through the stack assembly for separate connections. Thus, the interruptor type has two side arm connections through the base of the vibrator. The self-rectifier type has four side arm connections through the base of the vibrator.

The armature structure is not more than of an inch long by of an inch, and as shown in figures, comprises a vibratory reed assembly consisting of a rigid coldrolled steel armature member connected to a spring-steel hinge section 40 and two contact carrying spring members 16, 17. Two stopping or backing members 41 and 42, one on each side of the reed, are also included and are adapted to restrain and buffer the moveable side reed arm contacts as they are adapted to mate with the fixed side contacts of the vibrator.

The reed arm 14 of the vibrator is of extremely small dimensions and has a rectangular frame configuration with its top bent substantially horizontally. The armature end 15 is connected to the reed by means of a shoulder portion. The frame is connected to the hinge of the vibrator by means of its bottom side 75 which is adapted to be welded to the hinge. '"Ihe reed arm and armature are integrally connected with the bottom to form a unitary structure. On each side of the armature and reed are the reed contact springs 16, 17 which are joined to the reed by means of rivets which penetrate a pair of spaced apertures. Each spring or arm has a bottom base portion and a centrally connected finger for carrying the individual contacts thereon. The finger has its top portion slightly angulated with respect to its lower portion.

Rectangular shaped, individual backing members 41, 42 are provided for each of the arms 16 and 17. These backing members also have a frame configuration having integrally joined sides connected to the top and bottom thereof. These sides encompass a considerable rectangular cut-out. The bottom side, like the armature reed and the reed contact arms, has a pair of apertures designed to allow rivets to interconnect the parts. The top side of one of the backing frames when riveted, directly underlies the armature and bears against the reed contact arms at a point directly above the contact whereby its function as a biasing and stopping member is obtained. On the other side, the rectangular frame top 81 lies against the reed arm at a point above that of the contact. The entire armature assembly is connected to the hinge by the rivets passing through the apertures.

It will be seen, hereafter, that the assembly, supra, as mounted on the hinge is connected and held tightly in the stack support 31. The stack support tightly mounts the armature assembly and the .fixed side contact arms rigidly within the vibrator casing. This stack support comprises a main collar section 52 and an associated end closure 55 adapted to fit up against the ends of the collar to form a closure therefor. The periphery of the collar 52 has a semi-circular contour whereas its inner walls form a rectangular cut-out. The stack end closure 55 abuts the collar section with the outer peripheral portion continuing the arc thereof with its end 85 being truncated. Both sections of the stack have a pair of aligned apertures which are adapted to receive the stack screws 50, 51 which hold the hinge of the reed assembly and the two substantially 'fixed side arms 53, 54 for bolding the individual contacts thereupon. These side arms have a tapered configuration the tops of which hold the contacts wh'ch mate with the contacts on the reed arms. Each side arm comprises a base portion 86, a triangularly bent mid-section 87 connected thereto, and a finger section 88 carrying the individual contacts at the apex thereof. An electric terminal 89 extends vertically from the base of each side arm.

A stack washer 71 made of spring metal has the same truncated appearance of the stack support and cooperates therewith to provide additional aid in tightly supporting the entire assembly as it bears down against the shoulder of the cylindrical casing.

A threaded ring or plug 34 is inserted in the bottom of the casing and is adapted to be tightened therein so that a desired force may be exerted against the bottom of the stack assembly and to maintain the vibratory components in a rugged manner with relation to the driver coil and pole assembly. It is seen, too, that if necessary, the components may be easily removed for adjustments or test.

The theory behind the operation hereof is that when the vibratory reed armature is moved by excitation of the driver coil one contact pair will open and the armature will pass a maximum velocity point in its reed cycle. As the armature moves further in this direction, the other contact pair will make. At this point, there will be some loss, since the kinetic energy of translation of the contact mass must be dissipated. However, only the kinetic energy of the contact mass is lost since the rest of the mass of the system is separated by the compliance of the contact springs and this energy is stored as spring energy. Since the mass of the contact is a small percent of the overall mass of the armature, the net loss may be a very small percent of the energy stored in the armature system.

As the armature moves past the point of contact make, the kinetic energy of the armature mass, exclusive of the closed contact, is stored as spring energy in the contact spring and hinge. Neglecting a very small spring loss, substantially all of this energy is returned to the armature mass as the deflection decreases or the armature mass moves in an opposite direction. The present mechanism lends itself to good amplitudes so that it is substantially insensitive to small changes in contact spacings.

Thus, it has been found that the vibrator as fabricated in accordance with the above operational specifications had satisfactory operation with about .15 watt coil power at a frequency of 200 cps. This compared with about 1 watt of coil power for a vibrator operating at 115 cps. and with one at about 4 watts for a vibrator operating in a neighborhood of 250 cps. It is apparent that the trend toward miniaturization and transistorized applications reduces power supply requirements in such wise that vibrators must face the requirement of utilizing power supplies of 5 watts or less. Accordingly, the coil power of the vibrator becomes a major factor in the efiiciency of the power supply.

The present novel construction of the vibrator has been .found to attain optimum efficiency at high frequencies with the power supply component utilized therein being kept small. Vibrators built according to the present invention have been made which operate in the frequency range of 150 to 500 cps.

Although full wave vibrator circuits are ordinarily to be preferred in the usual power ranges, a half wave, separate drive circuit has been especially found adaptable for use in extremely low power application. Circuits utilizing this type of vibrator have an advantage from the fact that when an extremely low power system is to be used with a high internal resistance power source, as is apt to be found in dry batteries, the driver power does not disturb the regulation characteristics since the transformers utilized therein and the vibrators are energized during separate parts of the vibrator cycle. In addition thereto, its vibrator coil does not tend to load the primary of the transformer or affect the commutation of the transformer current. Either full wave or half wave rectification may be used in such circuits with full wave rectification being preferred in that there is better power supply efliciency. If necessary, capacitors for buffer action or point protection may be used as in ordinary circuit techniques.

However, if it is desired that larger amounts of power be used, then the power source resistance and the unbalance caused by transformer loading due to the vibrator coil becomes less important in the construction of the vibrator. Therefore, in that event, either full wave, separate drive or full wave, shunt vibrator constructions are feasible. It has also been found that in order to assure good vibrator life, contacts preferably made of molybdenum should be used when the power levels are high.

The present invention of a vibrator adapted for use in low power applications and in miniaturized circuits is taken to be representative thereof and not limiting inasmuch as the scope and applications thereof are to be gathered from the following claims.

What is claimed is:

1. A low loss vibrator mechanism adapted to operate in low power circuits under conditions of extreme acceleration and ruggedness comprising a cylindrical casing acting as a frame therefor, each end of which is internally threaded, individual shoulders formed internally at opposite end of said casing, said vibrator including a driver coil adapted to be current excited and having a pole piece penetrating through said coil, said pole piece being connected to an externally threaded plug adapted to be threaded into said casing and being adapted to rest on a shoulder of said vibrator in an extremely stable fashion, said plug being removable by counter-rotating the same, an armature and reed assembly comprising a vibratory reed having a hook-like armature bent from the free end thereof, a plurality of reed arms connected to said reed, said reed arms having contacts at the end thereof, a plurality of fixed side arms having contacts thereon placed on each side of said reed contact bearing arms and adapted to make contact therewith, a plurality of rectangular, frame, backing members for biasing said reed arms and means for supporting all of said above components of said assembly at the opposite end of said casing whereby an extremely rugged vibrator is provided.

2. A low loss vibrator mechanism adapted to operate in low power circuits under conditions of extreme acceleration and ruggedness comprising a cylindrical casing acting as a frame therefor, each end of which is internally threaded, individual shoulders formed internally at opposite ends of said casing, said vibrator including a driver coil adapted to be current excited and having a pole piece penetrating through said coil, said pole piece being connected to an externally threaded plug, said driver coil being circumscribed by a coil container whereby said plug having said pole piece is adapted to be threaded into said casing and being adapted to rest thereby on a shoulder of said vibrator in an extremely stable fashion, said pole piece being adjustable by rotation of said plug, an armature and reed assembly comprising a vibratory reed having a hook-like armature bent from the end thereof, a plurality of reed arms connected to said reed, said reed arms having contacts at the end thereof, a plurality of fixed side arms having contacts thereon placed on each side of said reed contact bearing arms and adapted to make contact therewith, and a plurality of rectangular, frame backing members for biasing said reed arms and means for supporting all of said above components of said assembly at the opposite end of said casing whereby an extremely rugged vibrator is provided.

3. A low loss vibrator mechanism adapted to operate in low power circuits under conditions of extreme acceleration and ruggedness comprising a cylindrical casing acting as a frame therefor, each end of which is internally threaded, individual shoulders formed internally at opposite ends of said casing, said vibrator including a driver coil adapted to be current excited and having a pole piece penetrating through said coil, said pole piece being connected to an externally threaded plug and vertically adjustable thereto by rotation of said plug, said driver coil being circumscribed by a coil container whereby said plug having said pole piece is adapted to be threadably inserted into threaded portion of said casing with said coil container being adapted to rest on said shoulder of said vibrator in an extremely stable fashion, an armature and reed assembly comprising a vibratory reed having a hook-like armature bent from its free end, a plurality of reed arms connected thereto, said reed arms having contacts at the end thereof, a plurality of fixed side arms having contacts thereon placed on each side of said reed arms adapted to make contact therewith, a plurality of rectangular, frame backing members for biasing said reed arms and means for supporting all of said above components of said assembly at the opposite end of said casing whereby an extremely rugged vibrator is provided.

4. A low loss vibrator mechanism adapted to operate in low power circuits under conditions of extreme acceleration and ruggedness comprising a cylindrical casing acting as a frame therefor, each end of which is internally threaded, individual shoulders formed at opposite ends of said casing, said vibrator including a driver coil adapted to be current excited and having a pole piece penetrating through said coil, said pole piece being connected to a threaded plug and vertically adjustable by rotation thereof, said driver coil being circumscribed by a coil container whereby said plug having said pole piece is adapted to be threadably inserted into said thread portion of said casing with said coil container being adapted to rest on a shoulder of said vibrator in an extremely stable fashion, an armature and reed assembly comprising a vibratory reed having an armature end thereof, a plurality of reed arms connected thereto, said reed arms having contacts at the end thereof, a plurality of fixed arms having contacts thereon placed on each side of said reed arms adapted to make contact therewith, a plurality of rectangular, frame backing members for biasing said reed arms and means for supporting all of said above components at the opposite end of said casing whereby an extremely rugged vibratory assembly is provided operable under extreme conditions of acceleration and ruggedness.

5. A low loss vibrator mechanism adapted to operate in low power circuits under conditions of extreme acceleration and ruggedness comprising a cylindrical casing acting as a frame therefor, each end of which is internally threaded, individual shoulders formed at opposite ends of said casing, said vibrator including a driver coil adapted to be current excited and having a pole piece penetrating through said coil, said pole piece being connected to a threaded plug, said driver coil being circumscribed by a coil container whereby said plug having said pole piece is adapted to be threadably inserted into said threaded portion of said casing with said coil container being adapted to rest on said shoulder of said vibrator in an extremely stable fashion, said pole piece being vertically adjustable by rotation of said plug, an armature and reed assembly comprising a vibratory reed having an armature at the end thereof, a plurality of reed arms connected thereto, said reed arms having contacts at the end thereof, a plurality of fixed arms having contacts thereon placed on each side of said reed arms adapted to make contact therewith, a plurality of rectangular, frame backing members for biasing said reed arms and stack means for supporting all of said above components at the opposite end of said casing, said stack means comprising a collar and a closure abutting the same, whereby an extremely rugged vibratory assembly is provided.

References Cited in the file of this patent UNITED STATES PATENTS 1,766,611 Day June 24, 1930 2,357,834 Leifer Sept. 12, 1944 FOREIGN PATENTS 274,993 Switzerland July 16, 1951 577,482 Great Britain May 20, 1946 

